Hereinbelow, the background art will be explained using as an example a semiconductor wafer.
Conventionally, the transferring of wafers between apparatuses for film formation (insulation film, conductive film), etching, cleaning, and the like, was conducted in the Following manner. That is to say, for example, upon completion of film formation, the wafer was removed from the film formation apparatus and placed within a clean room, the wafer was then placed on a wafer carrier 15 such as that shown in FIG. 6 or the like, and this was then moved within the clean room to the apparatus in which the subsequent processes were conducted, for example, an etching apparatus.
However, upon investigation by the present inventors, it was discovered that even within a clean room, when the wafer was exposed to the atmosphere, a natural oxide film was formed on the wafer surface, and that contaminant elements such as Na, Fe, and the like, became attached to the wafer surface. That is to say, it cannot be assumed that the environment within a clean room is always "clean".
Furthermore, when formation of a conductive thin film was conducted in a state in which this type of natural oxide film had been formed or such contaminant elements had been attached, there was a risk that contact resistances would be spoiled, and furthermore, when the formation of a thermal oxidation film was conducted, there was a risk that breakdown voltage characteristics would be spoiled.
The present invention:has as an object thereof to provide an apparatus for forming a thin film which does not spoil contact resistances and breakdown voltage characteristics.